Process of rust-proofing iron and steel by vapors containing phosphorus compounds.



nnnrnn snares PATENT onnrcn WILLIAM H. ALLEN, 01E DETROIT, MICHIGAN.

PROCESS OF RUST PRUOIFING: IRON AND STEEL BY VAEPOES CONTAINING- PHOSPHORUS COMPOUNDS.

L24Lfi1953 Specification of ietters Patent.

No Drawing. 1

To all whom it'may concern:

I specification; 110 l Be it known that l[, WILLIAM H. ALLEN, a citizen of the United States, and residing at Detroit, in the county of Wayne and State of Michigan, have invented a new and Improved Process of Rust-Proofing Tron an Steel by Vapors Containin Phosphorus Compounds, of which the fdllowing is a This invention relates to the treatment of articles of'iron and steel by means of vapors containing compounds of phosphorus in order that their surfaces may not be afiected by atmospheric conditions.

It has been suggested in the British patent to Ross, Number 3119 of October 27, 1869, that heated articles of iron and steel may be subjected to the action of vapors of phosphorus, but these vapors of elemental phosphorus are dificult to obtain and the treatment must take place in an atmosphere in which no free oxygen is present, that is, an atmosphere of nitrogen, carbon-dioxid or other inert gases. X

It is also known that basic phosphates of iron may be producedat the surface of articles of iron and steel by treating said articles with a solution of suitable acid phosphates, which basic phosphates will protect such articles from the oxidizing action of the atmosphere.

-The present invention consists in subjecting articles of iron and steel, properly cleaned by pickling or sand blast, to the fumes or vapors of phosphorus pento'xid or anhydrid together with some aqueous vapor until surfaces of basic phosphates of iron are produced. These vapors may be produced 1n any deslred manner, the preferred process consisting in subjecting a mixture of ground phosphate rock, coke and sand to a strong current in an electric furnace. The liberated phosphorus immediately chan es to P and these fumes are drawn into t e processing chamber by means of a suction fan. If desired, the fumes may be first passed through a dust chamber to remove impurities.

The processing chamber may be of any desired size and shape, dependi entirely upon the articles to be treated. t may be a revolving drum in which smallarticles are placed for treatment, which articles are moved by the turning of the drum to expose Application filed February 1, 1917., Serial Ito. 145,865.

all of their surfaces to the action of the fumes or vapors which thus prevents contact spots caused by one article lying against the other. ()r means may be installed Within the chamber to more the articles about and away from each other to prevent such contact spots.

The general method of producing the pentoxid of phosphorus fumes by means of an electric furnace is described in vol 9, No. 1 of The Journal of Industrial and Enginearing Chemistry, page 26.

A small jet of steam may meet the current of fumes or vapors of phosphorus 'pentoxid, causing the formation of phosphoric acid in a very fine state of division. Any other desired means may be employed to supply this aqueous vapor. The chamber should be so constructed that all of the fumes therein will be' in constant motion so that none of the acid will separate by grav- 1ty and settle to the bottom. If necessary,

fans or other devices may be installed to cause this constant movement of the vapors. The air and fumes may be drawn from the chamber and again passed through the furnace. This overcomes the dilution of the a charge of P 0,

en a sufficient amount of the phosphorus compound has been drawn into the chamber, the supply is out oh and the vapors are turned into another chamber and the articles being treated are left in the agitated vapors for a period of time varying from one to 'two or more hours. The vapors are then drawn from the chamber and passed through the furnace to another chamber, or they may be passed through or over sodium carbonate or hydrate to form. the marketable phosphate of sodium. Or these vapors may be precipitated or conserved in any other desired manner.

If desired commercial phosphoric anhydrid may be volatilized and the vapors thereof passed directly to the processing chamber as above described and therein mixed with steam and kept in motion.

I claim 1. The process of treating articles of iron and steel to prevent them from rusting which consists in subjecting them in a closed chamber to the action of finely divided phosphoric acid suspended in the atmosphere of the chamber.

and steel to prevent them from rusting which consists in subjecting them in a closed 2. The process of treating articles of iron chamber to the action o'f finely divided phosphoric acid suspended inthe atmosphere ber containingkthe articles to be treated and mingling said current with 4. The process of treating articles of-iron and steel to prevent them from rusting 15 which consists 1n passin a current ofphosphorus pentoxid'vapor nto a. closed chamber containing the articles to be treated and mingling said current with steam, and keeping the phosphoric acid resulting therefrom 20 in motion. 

